“Demi and Ashton had been receiving counseling from Kabbalah over the summer to try to fix their marriage,” a source told the show. Unfortunately, the couple is now living apart — so sad!

Star magazine reports 23-year-old Sara Leal‘s allegation that she slept with Ashton in San Diego, Calif., on Sept. 23 — his wedding anniversary! A source tells the mag: “Ashton and Demi have separated and the marriage is over.”

“I’m sick to my stomach over what happened,” the friend writes. “Ashton Kutcher f—-d my friend … in his room on the 12 floor of the Hardrock Hotel in San Diego. Ashton Kutcher told Sara Leal that him and Demi Moore are separated and the public doesn’t know yet.”

Furthermore, TheDirty.com reports there was even another girl in the room while Ashton slept with Sara — yikes!

An employee at San Diego’s Fluxx night club confirms to HollywoodLife.com that Ashton was there Sept. 23, celebrating his That ’70s Show co-star Danny Masterson‘s birthday, and that he left around 1:30 a.m.

“They had a VIP table,” the employee tells us. “It was right on the dance floor, conjoined with another table, and all the guys were drinking. I didn’t notice him talking to any girls.”

A public relations manager for the Hard Rock Hotel also confirms Ashton was there.

“I can confirm that he stayed both Friday and Saturday nights,” the manager tells us. “He was staying at the hotel with a group of friends.”

Allegedly, Sara is prepped to go public with the details of his infidelity soon.

“She is due to meet with an attorney [Tuesday]” an insider told the site. “She is freaking out.”

Demi and Ashton were recently spotted in NYC at the 60 Thompson hotel. “They stayed here about three weeks ago,” an insider tells. us. “I was in the elevator with them. They stayed in the suite upstairs. They seemed happy. They have stayed here before.”

And this isn’t the first time Ashton has allegedly cheated on Demi. Last year rumors swirled that he slept with 21-year-old aspiring chef, Brittney Jones.The story eventually disappeared (partly because it was widely reported Demi and Ashton have an “open relationship“) and they have appeared to be without problems ever since.

After that initial cheating accusation, Ashton took to Twitter to refute the rumors:

“I think Star magazine calling me a ‘cheater’ qualifies as defamation of character,” he tweeted in Sept. 2010. “I hope my lawyer agrees. STAR magazine – you don’t get to stand behind ‘freedom of the press’ when you are writing fiction.”

While we’d be shocked if the seemingly happy couple did decide to split, that certainly would explain the recent change in Demi’s physical appearance. We noticed that she was looking scary skinny at the premiere of her new movie Project Five, and if these rumors prove true, you could chalk all that weight loss up to stress.

Demi hasn’t been seen on a carpet with her hubby since the Stephen Weiss Apple Awards on June 9, and she tweeted a cryptic quote Sept. 23, leading her followers to speculate whether she knew something was up before the explosive report came out:

“When we are offended at any man’s fault, turn to yourself & study your own failings,” she tweeted. “Then you will forget your anger. -Epictetus”

Still, we really hope Sara Leal’s accusations turn out to be false!

We’ve contacted both Demi and Ashton’s reps and are awaiting responses.